A conventional inkjet printing system includes a printhead, an ink supply which supplies liquid ink to the printhead, and an electric controller which controls the printhead. The printhead ejects ink drops through a plurality of orifices or nozzles toward a print medium, such as a sheet or web of paper, so as to print onto the print medium. Typically, the nozzles are arranged in one or more arrays such that properly sequenced ejection of ink from the nozzles causes characters or the images to be printed upon the print medium as the print medium is moved relative to the printhead.
In one arrangement, commonly referred to as a fixed head printing system, one or more printheads are fixed or held stationary relative to the print medium as the print medium is advanced during printing. Depending on the printer system, one or more individual printheads can be included. If a plurality of individual printheads are utilized, the printheads are normally arranged in a staggered configuration to form a printhead array which spans a nominal page width of the print medium. In a fixed head system, the print medium, such as a continuous web of material or a cut sheet paper supply, is moving under the nozzles of the one or more printheads that remain fixed to the paper path.
In some fixed head printing system, depending on desired image resolution and system constraints, a user can print some images at a given print medium speed and some images at either higher or print medium speeds using a print medium speed controller in the print medium path. If the user selects a lower speed, the optical density or resolution of the printed image does not change, even if system constraints allow the plurality of nozzles of the printhead to fire more ink to achieve a better image resolution. Conversely, if the user selects a print medium speed faster than the system can accommodate at a chosen image resolution, the printer system stops firing ink, thereby stopping the printing in order to maintain the integrity of the nozzles of the printhead.